Dissertation > Industrial Technology > Light industry,handicrafts > Food Industry > Aquatic products processing industry > Aquatic food processing and preservation

Study on Hydrolysis Processing of Squid and Its Hydrolysates

Author JiangJianMei
Tutor JiaShiRu
School Tianjin University of Science and Technology
Course Biochemical Engineering
Keywords squid squid hydrolysate antioxidative activity functional properties HighFischer Ratio Oligopeptide
CLC TS254.4
Type Master's thesis
Year 2010
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Squid was subjecet to denaturation by heat treatment. Then five kinds of endogenous proteases were used to hydrolyze squid, among which, papain and flavorenzyme have been selected. The optimum hydrolysis conditions of papain and flavorenzyme were obtained by orthogonal experiment design. Bienzyme hydrolysis was adpted considering the limitage of single protamex. Under the optimized conditions, which were temperature55℃, pH6.0, the ratio of papain and pepsin was1:2, DH was up to34.5%.Two methods, enzyme hydrolysis and non-enzyme hydrolysis, were compared in terms of in vitro antioxidation, with the result as, enzyme hydrolyzed powder was advantageous over non-enzyme treated one. With hydrolyis proceeding, DH increased gradually then reached to a plateau; nitrogen solubility index (NSI) grew progressively. Superoxide anions, hydroxyl free radicals and DPPH were scavenged effectively by squid hydrolysates, whereas, the optimum scavenge was reached at different hydrolysis time for every free radical.For antioxidative activity, enzymatic of squid powder was higher than un enzymat-ic.During the process of hydrosis, emulsification of hydrolyzates showed an increasing trend, and the emulsification stability increased, but foamability increased first then decreased.Hydrolyzate lossed its antioxidation activity at pH2.0. Only3.37%of activity was remained. The antioxidant stabilities by sucrose, glucose and malt dextrin were94~95%; the stabilities induced by pullan and trehalose were96~97%. Pullulan and trehalose on the antioxidant stability of hydrolysate maintained at96~97%. Biological presevatives were better than sodium benzonate in terms of antioxidant stability, at the same time, the antioxidant stability gradually decreased with its dosage. With the mass fraction of the increase, the antioxidant stability of hydrolysate was gradually decrease.The squid viscera hydrolates, which had been two-step enzymatically hydrolyzed, were treated by active carbon. High Fischer Ratio Oligopeptide (4.58) was obtained. Spray dried squid powder was produced in pilot test.

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